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Posted

Noticed this in the internals pic of a merging nadac circled in red.  Hmmm. those guys probably know nothing or are just doin it for audiofoolery I guess..

 

image.png.073595aada3cbc548641cc51a0c743bf.png

 

Posted (edited)
11 hours ago, frednork said:

Noticed this in the internals pic of a merging nadac circled in red.  Hmmm. those guys probably know nothing or are just doin it for audiofoolery I guess..

 

image.png.073595aada3cbc548641cc51a0c743bf.png

 

 

The only reason to do that is to pass emc testing for ce, FCC, tick certification.  The design was probably externally "leaking" RF.

 

It won't be for a sound quality issue.  The ferrite on the cable won't stop the Ethernet board itself emitting RF within the case.

 

Edited by March Audio
  • Like 3
Posted (edited)
22 hours ago, frednork said:

Noticed this in the internals pic of a merging nadac circled in red.  Hmmm. those guys probably know nothing or are just doin it for audiofoolery I guess..

 

image.png.073595aada3cbc548641cc51a0c743bf.png

 

 

Its not uncommon to see ferrite on network cables,  as per above post its there to ensure compliance, one of our products has this too.  See the sticker on the audio pcb, it has a FCC and a CE compliance symbol.   

Not that i trust manufacturers measurements,  but here it is, they have given measurements for the 8-channel version, and where did they take the measurements; at the analog output of the dac:

NADAC-8ch-Noise-floor.jpg

NADAC_8ch FFT_1kHz_0dBFS.jpg

Edited by Addicted to music
Posted
On 01/05/2024 at 11:29 PM, March Audio said:

 

The only reason to do that is to pass emc testing for ce, FCC, tick certification.  The design was probably externally "leaking" RF.

 

It won't be for a sound quality issue.  The ferrite on the cable won't stop the Ethernet board itself emitting RF within the case.

 

But one thing the ferrite bead will do is knock the nice sharp corners off the data square waves. It actually degrades the data signal to a degree, depending on the suppressor type.

 

This video gives a bit of an explaination of the effect of ferrite beads on cables, especially as it relates to data signals at around the 4:00 mark.

 

 

Posted (edited)
21 minutes ago, bob_m_54 said:

But one thing the ferrite bead will do is knock the nice sharp corners off the data square waves. It actually degrades the data signal to a degree, depending on the suppressor type.

 

This video gives a bit of an explaination of the effect of ferrite beads on cables, especially as it relates to data signals at around the 4:00 mark.

 

 

 

Ferrite beads are  low pass filters,  yes you will see this effect on nearly everything you place them on,  however if the transmission markers are getting through and are still within the specifications where the receiver is recognising it: whats the problem?   Designers are not going to use the wrong values to the point where it distorts it that bad so it doesnt work.  its not like the OP going blindfolded without real measurements or real equipment like oscilloscopes, analysers and eye diagrams to see whats happening.  

Edited by Addicted to music
Posted
12 hours ago, Addicted to music said:

 

Ferrite beads are  low pass filters,  yes you will see this effect on nearly everything you place them on,  however if the transmission markers are getting through and are still within the specifications where the receiver is recognising it: whats the problem?   Designers are not going to use the wrong values to the point where it distorts it that bad so it doesnt work.  its not like the OP going blindfolded without real measurements or real equipment like oscilloscopes, analysers and eye diagrams to see whats happening.  

There is no problem, but what I was trying to illustrate is that the only thing the ferrite bead on the cable will do, apart from suppress HF radiation from that cable, and suppress passing through HF noise from one unit to another, is to degrade the data signal, to a degree (the more you use and more different types, will degrade the signal even more.

 

This is actually not really a problem for most data transmission systems, much to the surprise of many "audiophiles", as digital data transmission systems are very robust and well proved.

 

But in context of the OP, it will do more harm than good, due to excessive bending of the cable around the toroids, and the over zealous use of ferrites.

Posted
On 1/5/2024 at 10:59 PM, March Audio said:

 

The only reason to do that is to pass emc testing for ce, FCC, tick certification.  The design was probably externally "leaking" RF.

 

It won't be for a sound quality issue.  The ferrite on the cable won't stop the Ethernet board itself emitting RF within the case.

 


Exactly right.

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